A270821 Numbers n such that F(n) - n is a prime, where F(n) denotes the n-th Fibonacci number.

6, 8, 16, 26, 28, 76, 148, 159, 808, 848, 916, 1143, 4036, 4959, 43239, 73432, 98716, 144039, 146132

Offset

1,1

Links

Table of n, a(n) for n=1..19.

Example

fibonacci(6) - 6 = 8 - 6 = 2 that is a prime;
fibonacci(8) - 8 = 21 - 8 = 13 that is a prime.

Maple

with(combinat): P:=proc(q) local n;
for n from 0 to q do
if isprime(fibonacci(n)-n) then print(n); fi; od; end: P(10^5);

Mathematica

Select[Range[150000], PrimeQ[Fibonacci[#]-#]&] (* Harvey P. Dale, May 03 2018 *)

Prog

(PARI) lista(nn) = {for(n=1, nn, if(ispseudoprime(fibonacci(n)-n), print1(n, ", "))); } \\ Altug Alkan, Mar 30 2016

Crossrefs

Cf. A000045, A065220, A064269, A069109, A175404.

Sequence in context: A067543 A006583 A011989 * A139452 A245643 A299030

Adjacent sequences: A270818 A270819 A270820 * A270822 A270823 A270824

Keyword

nonn,more

Author

Paolo P. Lava, Mar 30 2016

Extensions

a(15)-a(19) from Giovanni Resta, Apr 14 2016

Status

approved